No visible fermentation activity after 12 hours

I brewed a Brewers Best India Black Ale yesterday afternoon. 12 hours have passed since pitching my yeast and there is absolutely not activity in the carboy. Is it possible that I shocked my yeast when I rehydrated? The water that I used to rehydrate this dry yeast was probably around 90 degrees, then pitched into wort that was between 60-70. I gave the carboy a good shake after I pitched. I am a little nervous because I fully expected it to be rocking this morning.

What yeast did you use? I've had US-04 and US-05 take up to 36hrs before showing signs. Nottingham seems to get started a lot faster. However, I've never rehydrated. Give it some time. Relax. Don't Worry. Have a Home Brew.

i second the 'give it some time'---24-36 hours is fair if you don't have a big starter i think. i pitched on yeast cake last month for the first time & the fridge sounded like mortar rounds after just three hours...

I used a Danstar Dry-97. I used the same yeast a couple of weeks ago in a red ale and it was going crazy 12 hours later. I'll give it some time....I know the motto

What temp is the carboy at? It is good to keep it a little warm maybe 68 until the fermenation starts. Give it some more time before you re-pitch.

I don't think shocked the yeast by rehydrating - that's very unlikely. As long as you didn't put it in a scalding hot water it will be fine. Might want to wait a little bit longer. Although I generally see the signs within the first 12 hours it's not unusual that it could take longer , like 24 or 36. Also, like kevinb says - check the fermentation temp.

Read this thread and give it some time

https://www.homebrewtalk.com/f39/fermentation-can-take-24-72-hrs-show-visible-signs-43635/

FWIW when I pitched dry yeast into my last batch I never actually saw any activity take place. I did a gravity reading 72 hours after pitching and sure enough it was darn near all the way to FG.

I've had batches sit idle for up to 72 hours before finally going to work. Keep in mind that just because it doesn't look like much is happening doesn't mean it isn't. There isn't much to see during the "lag" phase, but the yeast is quietly building its numbers and getting ready to gorge themselves on the buffet of sugars you've provided them.

Thanks for the help, guys. I think my main issue is temp. It's colder now in the closet where I ferment than it has been for any of my previous batches. I am gonna try to warm the closet up a bit, but may move my carboy to a different area in the morning if I don't see anything happening. My biggest problem is patience....

Looks like the yeast is going to work. When I got home from work this evening, there was foam starting to form on top and I heard a couple of bubbles coming from the blowoff tube. It took about 48 hours from when I pitched my yeast. Gonna relax and have a homebrew.